search
HomeDatabaseMysql Tutorialconnection .server version引发了system.invalidOperationExcep

这个问题查找了一整天,在这个博客上找到了答案。错误不再报了,但是仍在调试中。。。 先贴solution。 -------------------------------------------------------------------------------------------------- 问题在于:State Closed System.Data.Connectio

这个问题查找了一整天,在这个博客上找到了答案。错误不再报了,但是仍在调试中。。。

先贴solution。

--------------------------------------------------------------------------------------------------

问题在于:State Closed System.Data.ConnectionState
连接没有open().

在try中加入
if (oleDbConnection1.State != ConnectionState.Open)
    oleDbConnection1.Open();

加上
finally
{
    if (oleDbConnection1.State != ConnectionState.Close)
    {
        oleDbConnection1.Close();
    }
}

”----引自

---------------------------------------------------------------------------------------------------------------------------

做了一些小的改动,因为是在cs文件中调用自己写的一个ExecuteReader方法,因此最后的sql连接不能关闭。

贴这个方法的代码。

======================================================================

public bool ExecuteReader(string queryString,string procName,out SqlDataReader myReader)

{

...

SqlConnection connection=new SqlConnection(connectionString);

try

{

if(connection.state!=connectionstate.open)

connection.open();

sqlcommand cmd=new sqlcommand(procName,connecetion);

cmd.commandType=commandType.StoredProcedure;

//添加存储过程参数。。。

myReader=cmd.ExcuteReader();

}

catch(exception e)

{throw e;}

return true;

}

=============================================================

另。数据库的连接可以用下面这种:

using (sqlconnection conn=new sqlconnection (connectionstring))

{

using(sqlcommand cmd =new sqlcommand(procName,conn))

...

}

但是这里不能用。因为这种方法的连接在using结束之后自动断开,当主程序访问类中的这段方法时会报错

:“连接关闭”什么的。

using方法在其他地方还是不错的。自动断开,多好~嘿嘿

**********************************************************************

相关问题

因为这个错误,查了一下web.config里面connectionstring的问题。

以下转自。

web.config connectionStrings 数据库连接字符串的解释(转载)

先来看一下默认的连接SQL Server数据库配置

  

SqlConnectionStringBuilder实例化时需要使用connectionString。如:SqlConnectionStringBuild builder = new SqlConnectionStringBuild(connectionString);


一、Data Source
SqlConnectionStringBuilder的DataSource属性,对应 connectionString中的Data Source,“Data Source”可以由下列字符串代替:“Server”,“Address”,“Addr”和“Network Address”。
Data Source=.\SQLExpress也可以写成这样Data Source=(local)\SQLExpress。

二、Integrated Security
SqlConnectionStringBuilder 的 IntegratedSecurity 属性,对应 connectionString 中的I ntegrated Security,虚拟主机,“Integrated Security”可以写成“trusted_connection”。
为 True 时,使用当前的 Windows 帐户凭据进行身份验证,为 False 时,需要在连接中指定用户 ID 和密码。可识别的值为 True、False、Yes、No 以及与 True 等效的 SSPI。
如果没有些则必须写上 uid=sa;pwd=123 之类的设置“uid”也可使用“User ID”,“pwd”也可换为“PassWord”。

SSPI:Microsoft安全支持提供器接口(SSPI)是定义得较全面的公用API,用来获得验证、信息完整性、信息隐私等集成安全服务,以及用于所有分布式应用程序协议的安全方面的服务。
应用程序协议设计者能够利用该接口获得不同的安全性服务而不必修改协议本身。

三、AttachDBFilename
SqlConnectionStringBuilder 的 AttachDBFilename 属性,对应 connectionString 中的 AttachDBFilename,“AttachDBFilename”可以写成“extended properties”,“initial file name”。
AttachDbFileName 属性指定连接打开的时候动态附加到服务器上的数据库文件的位置。
这个属性可以接受数据库的完整路径和相对路径(例如使用|DataDirectory|语法),在运行时这个路径会被应用程序的 App_Data 目录所代替。

四、User Instance
SqlConnectionStringBuilder 的 UserInstance 属性,对应 connectionString 中的 User Instance ,该值指示是否将连接从默认的 SQL Server 实例重定向到在调用方帐户之下运行并且在运行时启动的实例。
UserInstance=true 时,SQLServerExpress 为了把数据库附加到新的实例,建立一个新的进程,在打开连接的用户身份下运行。
在 ASP.NET 应用程序中,这个用户是本地的 ASPNET 帐号或默认的 NetworkService,这依赖于操作系统。
为了安全地附加非系统管理员帐号(例如ASP.NET帐号)提供的数据库文件,建立一个独立的 SQLServer 用户实例是必要的。

五、Initial Catalog 等同于 Database。

六、providerName 指定值“System.Data.OracleClient”,该值指定 ASP.NET 在使用此连接字符串进行连接时应使用 ADO.NET System.Data.OracleClient 提供程序。


PS:
DataDirectory是什么?

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Reduce the use of MySQL memory in DockerReduce the use of MySQL memory in DockerMar 04, 2025 pm 03:52 PM

This article explores optimizing MySQL memory usage in Docker. It discusses monitoring techniques (Docker stats, Performance Schema, external tools) and configuration strategies. These include Docker memory limits, swapping, and cgroups, alongside

How to solve the problem of mysql cannot open shared libraryHow to solve the problem of mysql cannot open shared libraryMar 04, 2025 pm 04:01 PM

This article addresses MySQL's "unable to open shared library" error. The issue stems from MySQL's inability to locate necessary shared libraries (.so/.dll files). Solutions involve verifying library installation via the system's package m

How do you alter a table in MySQL using the ALTER TABLE statement?How do you alter a table in MySQL using the ALTER TABLE statement?Mar 19, 2025 pm 03:51 PM

The article discusses using MySQL's ALTER TABLE statement to modify tables, including adding/dropping columns, renaming tables/columns, and changing column data types.

Run MySQl in Linux (with/without podman container with phpmyadmin)Run MySQl in Linux (with/without podman container with phpmyadmin)Mar 04, 2025 pm 03:54 PM

This article compares installing MySQL on Linux directly versus using Podman containers, with/without phpMyAdmin. It details installation steps for each method, emphasizing Podman's advantages in isolation, portability, and reproducibility, but also

What is SQLite? Comprehensive overviewWhat is SQLite? Comprehensive overviewMar 04, 2025 pm 03:55 PM

This article provides a comprehensive overview of SQLite, a self-contained, serverless relational database. It details SQLite's advantages (simplicity, portability, ease of use) and disadvantages (concurrency limitations, scalability challenges). C

Running multiple MySQL versions on MacOS: A step-by-step guideRunning multiple MySQL versions on MacOS: A step-by-step guideMar 04, 2025 pm 03:49 PM

This guide demonstrates installing and managing multiple MySQL versions on macOS using Homebrew. It emphasizes using Homebrew to isolate installations, preventing conflicts. The article details installation, starting/stopping services, and best pra

How do I configure SSL/TLS encryption for MySQL connections?How do I configure SSL/TLS encryption for MySQL connections?Mar 18, 2025 pm 12:01 PM

Article discusses configuring SSL/TLS encryption for MySQL, including certificate generation and verification. Main issue is using self-signed certificates' security implications.[Character count: 159]

What are some popular MySQL GUI tools (e.g., MySQL Workbench, phpMyAdmin)?What are some popular MySQL GUI tools (e.g., MySQL Workbench, phpMyAdmin)?Mar 21, 2025 pm 06:28 PM

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

PhpStorm Mac version

PhpStorm Mac version

The latest (2018.2.1) professional PHP integrated development tool

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.